This invention relates to conveyors, and more particularly, it concerns power driven roller conveyors for unscrambling randomly arranged cartons, aligning the cartons in single file and orienting the cartons along their long axes.
A variety of unscrambler type conveyor systems are presently known. These unscramblers generally arrange randomly received cartons in single file prior to delivery to a take-off conveyor. For example, U.S. Pat. No. 3,866,739 to Sikorski, entitled FREE FLOW DEVICE FOR CONTAINER UNSCRAMBLERS, issued on Feb. 18, 1975 discloses an unscrambling device including a plurality of longitudinally extending conveyor belts and an angled oscillating shunting bar. Adjacent belts are driven at progressively increasing speeds to assist in separation of the randomly oriented containers. Further, the shunting bar extends across the belts at an acute angle relative to the unscrambler frame. As a result, the containers are driven into the shunting bar. The shunting bar directs the containers towards one side of the unscrambler to the outermost take-off belt. Should packages be placed on the unscrambler at too fast a rate, they will tend to jam up in the reduced area at the take-off conveyor. Oscillation of the shunting bar is necessary to jog the containers in an attempt to prevent such jamming.
Another prior unscrambler arrangement includes an elongated bed of power driven rollers. The bed is divided into a plurality of roller sections, with the roller sections being driven at a progressively greater speed from the receiving end to the discharge end. The interface between a pair of these sections is along an acute angle and is defined by a plurality of split rollers. A guard rail extends from one side of the conveyor bed inwardly at an acute angle opposite the direction of conveyor flow as in the Sikorski arrangement. Packages are deposited at one end of the unscrambler in a random fashion. As the packages pass over the interface they are separated and driven into the angled guard rail. The guard rail decelerates each package which comes in contact therewith and rotates it until it rests against the guard rail with the long axis in the direction of movement. This arrangement is subject to jamming at the reduced area where the packages or cartons are taken off the unscrambler. Angling of the guard rail relative to the conveyor bed results in a large area of the conveyor bed being totally unused for unscrambling or conveying purposes. This in conjunction with the angled guard rail reduces or limits the maximum rate at which packages may be randomly deposited on the unscrambler. Further, if a leading package is not adequately separated, it may hang up on a trailing package. The packages would then leave the conveyor in this condition which is not the desired, spaced, tandem orientation.